21414444397 has 2 divisors, whose sum is σ = 21414444398. Its totient is φ = 21414444396.

The previous prime is 21414444353. The next prime is 21414444421. The reversal of 21414444397 is 79344441412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16997379876 + 4417064521 = 130374^2 + 66461^2 .

It is a cyclic number.

It is not a de Polignac number, because 21414444397 - 2⁷ = 21414444269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21414444097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10707222198 + 10707222199.

It is an arithmetic number, because the mean of its divisors is an integer number (10707222199).

Almost surely, 2^21414444397 is an apocalyptic number.

It is an amenable number.

21414444397 is a deficient number, since it is larger than the sum of its proper divisors (1).

21414444397 is an equidigital number, since it uses as much as digits as its factorization.

21414444397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 43.

The spelling of 21414444397 in words is "twenty-one billion, four hundred fourteen million, four hundred forty-four thousand, three hundred ninety-seven".